Deck 8: Image Postprocessing and Visualization Tools

Question 1

Windowing in computed tomography is an example of:

A)a local processing operation
B)convolution
C)gray-level mapping
D)an image reconstruction algorithm

Answer 1

gray-level mapping

Question 2

When the window length is centered on the lungs, the image display is optimized for the lungs.

Answer 2

True

Question 3

One major disadvantage of multiplanar reconstruction is that images are not as good as those obtained in transaxial images.

Answer 3

True

Question 4

Image smoothing is an example of a linear image manipulation technique.

Question 5

The window width in computed tomography is the:

A)center of a range of computed tomography numbers
B)pixel depth
C)range of computed tomography numbers
D)dimension of the matrix

Question 6

Which of the following fall into the category of a linear image manipulation technique(s)? I. image enhancement
II) contrast stretching
III) image smoothing

A)I and II
B)II and III
C)I and III
D)I, II, and III

Question 7

Which of the following determines the maximum number of gray shades to be displayed on the television monitor?

A)window level
B)window width
C)contrast controls on the television monitor
D)filtered back-projection algorithm

Question 8

A large window width means a long gray scale.

Question 9

Windowing does not make use of the computed tomography numbers.

Question 10

Windowing is an example of a linear image manipulation technique.

Question 11

As the window width decreases, the image contrast increases.

Question 12

Windowing is the most common image processing technique in computed tomography.

Question 13

Reconstruction synthesis operations create images from other images or nonimage data.

Question 14

A narrow window width implies that the transition from black to white will take place over a wide range of computed tomography numbers.

Question 15

Through the manipulation of computed tomography numbers of the various tissues, the picture can be changed to show soft tissues and dense structures such as bone.

Question 16

The range of computed tomography numbers is the window length.

Question 17

Gray-level mapping belongs to the class of:

A)point processing technique
B)local processing technique
C)global processing technique
D)geometrical processing technique

Question 18

Multiplanar reconstruction creates three-dimensional images from the transaxial data set.

Question 19

The computed tomography number for water is +1000.

Question 20

A narrow window width means fewer computed tomography numbers.

Question 21

Which of the following is a plot of the pixel values as a function of their frequency of occurrence?

A)region of interest statistics
B)computed tomography histogram
C)highlighting
D)multiple windowing

Question 22

As the window width increases, picture contrast:

A)increases
B)decreases
C)remains unchanged
D)is optimized to show the specific anatomical structures

Question 23

One industry standard in data transfer and connectivity is:

A)Digital Imaging and Communications in Medicine
B)hospital information system
C)radiology information system
D)picture archiving and communications system

Question 24

A large window width indicates that there is a relatively ______________ gray scale.

A)long
B)short
C)narrow
D)curved

Question 25

Which of the following optimizes the image display for a particular structure?

A)peak kilovoltage
B)milliamperage
C)window width
D)window length

Question 26

If the window width setting is 200 and the window length is 0, which of the following occurs?

A)computed tomography numbers greater than +100 appear white
B)computed tomography numbers less than 100 appear gray
C)computed tomography numbers between 0 and +200 appear black
D)only those numbers between +100 and +200 appear gray

Question 27

In which of the following are pixels in a certain region of the image made to appear brighter?

A)highlighting
B)image magnification
C)region of interest transfer
D)point-to-point imaging

Question 28

Which of the following belongs to the class of nonlinear image manipulation techniques?

A)image enhancement
B)image smoothing
C)gray-scale manipulation
D)linear smoothing

Question 29

Which advanced tool in computed tomography allows users to view a large set of images very quickly?

A)cine visualization
B)advanced quantitative measurement
C)interactive visualization
D)virtual reality visualization

Question 30

The window level in computed tomography is the:

A)center of a range of computed tomography numbers
B)pixel depth
C)range of computed tomography numbers
D)center of the computed tomography matrix

Question 31

The window width and window length settings for a given examination of the abdomen are 400 and 0, respectively. Which of the following is true?

A)all structures between -200 and 200 will spread through the gray scale
B)all structures between -200 and 200 will be white
C)all structures between -200 and 200 will be black
D)only those structures above 400 will have different shades of gray

Question 32

Which of the following are categories of three-dimensional rendering? I. surface-shaded display
II) volume rendering
III) maximum and minimum intensity projections

A)I and II
B)II and III
C)I and III
D)I, II, and III

Question 33

Which of the following controls the contrast of the computed tomography image?

A)peak kilovoltage
B)milliamperage
C)window length
D)window width

Question 34

Which of the following are advantages to reformatted images? I. enable visualization of specific structures
II) determine true extent of lesions and fractures
III) provide images more pleasing to the eye

A)I and II
B)II and III
C)I and III
D)I, II, and III

Question 35

Which of the following generates sagittal, coronal, and paraxial images from transaxial slices?

A)back-projection reconstruction
B)filtered back-projection reconstruction
C)multiplanar reconstruction
D)radiation treatment planning computed tomography